| 摘要 |
PURPOSE:To prevent the C pickup contamination of an extra-low C steel by forming a titled nozzle into the two layers consisting of the fused silica used to constitute the inside where the nozzle does not contact with slag on a molten metal surface and the alumina graphite used to constitute the outside in contact with the slag. CONSTITUTION:The outside 12 of the immersion nozzle 1 where the nozzle contacts with the slag is made of the alumina graphite in order to obviate the increase in the erosion of a part 6 where the nozzle contacts with a slag line 5 on the molten metal surface. The inside 13 where the nozzle does not contact with the slag line 5 is made of the fused silica. The nozzle is further so shaped as to expand upward and is tapered at >=1.5mm/m to prevent a sleeve 11 consisting of the fused silica from falling during casting. The fused silica is formed to 7-30mm thickness at which the cracking thereof is obviated. |
